System and method for vacuum packaging goods

ABSTRACT

A sealing machine for sealing plant material disposed within a heat-sensitive bag comprises a first platen, a second platen movable with respect to the first platen between open and closed positions, and a compressible member disposed in a gap between said first and second platens. As the second member moves towards the closed position, the compressible member contacts and applies a pressure to bag, and evacuates substantially all of the air from within the bag without damaging the plant material. A sealing strip heats the bag, while an opposing pressure strip directs a pressure to the bag.

BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to packaging devices, andparticularly to devices used to vacuum package plant material within aheat-sensitive bag.

[0002] Vacuum packaging is a process that permits vendors, particularlythose of perishable goods, to substantially reduce shipping size, extendthe shelf life of their products, and optimize profits. Typically, thegoods are disposed within a heat-sensitive bag, and a pressure isapplied to force the air out of the bag. Once the air is evacuated fromthe bag, an open end of the bag is heat-sealed to prevent the goods fromfouling.

[0003] Despite the benefits, however, the process may actually bedamaging to some of the more fragile perishables. For example, currentdevices may employ pressures that can break or crush plant material,such as ferns and other plants used in the floral industry. As customersgenerally do not purchase floral arrangements having crushed or brokenplants, either the florists must dispose of the broken pieces, or theirsuppliers must ship plant material that is not vacuum packed. Thus, someindustries may not be able to realize the advantages offered by vacuumpackaging. Accordingly, there remains a need for a method and devicethat can vacuum-pack perishable materials without damaging thematerials.

SUMMARY OF THE INVENTION

[0004] The present invention relates to a method and apparatus ofsealing plant material within a heat-sensitive bag without damaging theplant material. In one embodiment, the apparatus comprises a firstplaten, a second platen movable with respect to the first platen betweenopen and closed positions, a gap between the first and second platenswhen the second platen is in the closed position, and a compressiblemember disposed in the gap. The plant material within the bag ispositioned on the first platen, and the second platen is moved towardsthe bag. The compressible member contacts and applies pressure to thebag, which evacuates substantially all of the air from within the bagwhile limiting the maximum amount of pressure applied to the plantmaterial. This prevents damage to the plant material. A sealing stripthen cooperates with an opposing pressure strip to seal the bag.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]FIG. 1 illustrates one embodiment of the present invention.

[0006]FIG. 2 illustrates sealing plant material within a bag accordingto one embodiment of the present invention.

[0007]FIG. 3 illustrates an alternate embodiment of the presentinvention.

[0008]FIG. 4 illustrates sealing plant material within a bag accordingto an alternate embodiment of the present invention.

[0009]FIG. 5 illustrates an exemplary sealed product wherein floralplant material has been sealed within a bag using the method andapparatus of one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0010] Referring now to FIG. 1, one embodiment of the sealing machine ofthe present invention is shown therein, and indicated generally by thenumber 10. In this embodiment, sealing machine 10 is used to seal anobject in a bag, for example, plant material 12 in bag 14. Sealingmachine 10 comprises a first platen 16, a second platen 18, acompressible member 20, a pressure strip 24, and an opposing sealingstrip 26. One or more hinges 28 may connect the first and second platens16, 18, while electrical control 30 and foot pedal 32 control theoperation of the sealing machine 10.

[0011] The bag 14 may be made of any variety of flexible, plastic film.Plastics such as polyethylene, polypropylene, polyvinylchloride, orpolystyrene, as well as any other type of material known in the art, aresufficient for use in the construction of bag 14. Further, bag 14 may beof any thickness to provide the desired rigidity, resistance topuncture, and optimum gas exchange through the walls of bag 14.

[0012] Electrical control 30 connects via power cord 34 to an externalpower source (not shown), and provides power to heat the sealing strip26 and operate the first and second platens 16, 18. A control knob 36located on the front panel of electrical control 30 allows a user toadjust the amount of pressure and/or temperature applied to the plantmaterial 12 and bag 14, respectively, while gauge 38 permits the user tomonitor the pressure and/or temperature. In one embodiment, electricalcontrol 30 comprises an 800-Watt transformer, but those skilled in theart will readily appreciate that electrical control 30 may comprise anycomponent known in the art that will provide regulated power.

[0013] Foot pedal 32 operatively connects to one or more fluid cylinders40, which, in turn, connect to an external compressor (not shown) viahose 42. When the user depresses foot pedal 32, the external compressorcauses the fluid cylinders 40 to move the second platen 18 into theclosed position. Conversely, releasing foot pedal 32 causes the secondplaten 18 to move into the closed position.

[0014] The fluid cylinders 40 are pneumatic cylinders capable ofproviding up to about 100 psi. A pressure relief valve (not shown)disposed on each fluid cylinder 40 regulates the maximum amount ofpressure, and helps prevent damage to the fluid cylinders 40 due torepeated pressure buildup. The pressure relief valve also enables thefluid cylinders 40 to provide the rated pressing force (e.g., 100 psi),and finish with a zero-compression ratio when bag 14 is sealed. However,the present invention is not limited merely to using pneumatic cylindersrated at 100 psi. Those skilled in the art will readily appreciate thatthe fluid cylinders 40 may also be hydraulic cylinders, for example, andfurther, rated for any pressure desired. As will be explained later inmore detail, the compressible member 20 will prevent damage to the plantmaterial, regardless of the amount of force applied by fluid cylinders40.

[0015] Sealing strip 26 may be constructed from a nichrome base with acopper and ceramic strip, and is dimensioned to provide heat over anarea sufficient to seal bag 14. For example, the embodiment of FIG. 1illustrates the sealing strip 26 as approximately 1 cm. wide andintegrally formed along an edge of first platen 16. Alternatively,however, sealing strip 26 may be integrally formed along an edge ofsecond platen 18. In fact, as will be described later in more detail,sealing strip 26 need not be attached to the first or second platens 16,18, but instead, exist as a separate entity distinct from the first andsecond platens 16, 18. Thus, those skilled in the art will readilyappreciate that the size, configuration, and materials used in theconstruction of sealing strip 26 may vary.

[0016] As stated above, electrical control 30 provides power to heat thesealing strip 26. Further, the user may vary and monitor the temperatureof the sealing strip 26 via control knob 36 and gauge 38. Thus, the usermay raise or lower the temperature of the sealing strip 26 as needed. InFIG. 1, the temperature may vary anywhere from 0° Celsius (e.g., whenthe sealing strip 26 is turned off) to about 100° Celsius, and typicallyranges from about 40° Celsius to about 90° Celsius in operation. Atemperature of about 60° Celsius applied for about 5 seconds, however,should be sufficient with which to seal bag 14 shown in FIG. 1. Ofcourse, as the present invention is not limited to the use of any onetype of bag 14, it is also not limited to any single range oftemperatures. That is, sealing strip 26 may be controlled to heat to anytemperature, dictated for example, by the specific properties ofwhatever bag 14 is employed.

[0017] Pressure strip 24 may comprise a hardened bar of material, suchas wood, metal, or metal alloy, but other materials may also be used.For example, foam having various densities, and rubber, are materialsthat are equally sufficient with which to construct the pressure strip24. Whatever the material used, however, should be of a sufficienthardness to permit the user to apply prolonged pressure to bag 14without tearing the bag 14. A leather or vinyl cover may cover part orsubstantially all of pressure strip 24 to help prevent damage to the bag14.

[0018] The pressure strip 24 of FIG. 1 opposes the sealing strip 26.Like sealing strip 26, pressure strip 24 may be integrally formed alongthe edge of the second platen 18, the first platen 16, or existseparately from the first and second platens 16, 18 altogether. Whateverthe configuration, pressure strip 24 should oppose sealing strip 26 toprovide the requisite pressure to the selected portion of the bag 14disposed on sealing strip 26. In FIG. 1, pressure strip 24 lowers inconcert with the second platen 18, and remains in contact with theselected portion of the bag 14 for as long as the second platen 18remains in a closed position. While the time required for sealing bag 14may depend on such factors as the properties of the bag 14 (e.g.,thickness, material, etc.), and amount of heat applied to the bag 14, itis generally within the range of about 1-20 seconds, and typicallywithin the range of 1-10 seconds.

[0019] Compressible member 20 is disposed in the gap 22 formed betweenthe first and second platens 16, 18 when the second platen is in theclosed position (FIG. 2). Preferably, compressible member 20 isconstructed of a pliable, resilient material of sufficient density ableto withstand the compressions and decompressions associated with therepeated opening and closing of the first and second platens 16, 18.Compressible member 20 prevents damaging the plant material 12 withinbag 14 during the packaging process, while still providing sufficientpressure with which to evacuate the air from within the bag 14. Thisability to protect plant material 12 is, of course, irrespective of theamount of force with which fluid cylinders 40 may operate.

[0020] For example, in one embodiment, the fluid cylinders 40 operate atpressures of about 100 psi to move the second platen 18 towards theclosed position. As the compressible member 20 contacts the bag 14, itevacuates substantially all of the air from within the bag 14, andcollapses around the plant material 12 thereby preventing the plantmaterial 12 from being crushed. Thus, the compressible member 20 limitsthe maximum amount of force applied to the plant material 12 within bag14. While the maximum amount of force may vary according to the device,or type of compressible member 20, in one embodiment the maximum amountof force is limited to the range of about 5 lbs. per square inch toabout 20 lbs. per square inch.

[0021]FIG. 1 illustrates compressible member 20 attached to the secondplaten 18, but may alternatively be attached to the first platen 16.Attachment may be accomplished using any means known in the artincluding, but not limited to, glue and mechanical fasteners. Further,the present invention is not limited to the use of a single compressiblemember 20, but also may include a second compressible member (notshown). In this embodiment, each of the first and second platens 16, 18could include a compressible member 20 attached to it. Whatever thenumber of compressible members 20 used, however, they operate to limitthe maximum amount of force applied to the plant material 12 when thesecond platen 18 is in the closed position, and thus, prohibits damageto the plant material 12.

[0022] In operation, the user places plant material 12 within bag 14.Typically, bag 14 has already been sealed on three sides; however, thoseskilled in the art will realize that “pre-sealing” bag 14 is notnecessary. In fact, plant material 12 may be simply disposed between twosheets of material, and the sealing machine 10 of the present inventionused to seal all the sides. Further, the user has already adjusted thetemperature of sealing strip 26 and/or the amount of pressure applied bycylinders 40 using electrical control 30, but this is not necessary.

[0023] The plant material 12 within bag 14 is disposed on the surface offirst platen 16, and positioned such that a portion of the open end ofbag 14 lies outside of the confines of the compressible member 20 andover sealing strip 26. As seen in FIG. 1, the plant material 12 liescompletely within the confines of the compressible member 20, such thatcompressible member 20 will completely envelop plant material 12 whenthe second member 18 closes.

[0024] Once positioned, the user depresses foot pedal 32, which operatesthe fluid cylinders 40 to move the second platen 18 from the openposition to the closed position, as seen in FIG. 2. As the second platen18 closes, compressible member 20 presses down on the plant material 12within bag 14, and causes substantially all the air to evacuate throughand out the open end of bag 14. In accordance with the presentinvention, compressible member 20 collapses around plant material 12,thereby limiting the maximum amount of applied pressure and prohibitingany damage to the plant material 12.

[0025] When the second platen 18 reaches the fully closed position, thepressure strip 24 contacts and applies pressure across the selectedportion of bag 14 that extends over the heated sealing strip 26. Thepressure strip 24 may be slightly offset from the plane of the secondplaten 18 to compensate for the gap 22 that is formed when the secondplaten 18 fully closes. In this embodiment, the sealing strip 26 isheated to about 60° Celsius, and the second platen 18 remains in theclosed position for about 5 seconds to seal the open end of bag 14.However, no substantial amount of heat is ever transferred to the plantmaterial 12 within the bag 14. When complete, the user releases footpedal 32, and second platen 18 returns to the open position. Thus, theopen end of the bag 14 is sealed, ambient air is substantially preventedfrom entering the inside of bag 14, and the plant material 12 within bag14 remains free from damage presenting a substantially vacuum-packedappearance.

[0026]FIG. 3 illustrates an alternate embodiment of the presentinvention, which employs neither fluid cylinders 40, nor a foot pedal 32to operate the first and second platens 16, 18. Instead, the usermanually moves the second platen 18 from the open position to the closedposition. Further, both the sealing strip 26 and the pressure strip 24are associated with a heating unit 44, and are separate from the firstand second platens 16, 18. Accordingly, neither the sealing strip 26 northe pressure strip 24 move with the second platen 18. Like electricalcontrol 30, heating unit 44 connects to a power source (not shown), andregulates the temperature of the sealing strip 26. As in the previousembodiments, plant material 12 disposed within bag 14 is placed on thefirst platen 16 with an open end of bag 14 placed over the sealing strip26, such that compressible member 20 will envelop plant material 12 whenthe second platen 18 is fully closed.

[0027] As seen in FIG. 4, the user operates sealing machine 10 bymanually lowering the second platen 18. Compressible member 20pressingly engages the plant material 12, and substantially evacuatesall of the air through and out the open end of bag 14. As compressiblemember 20 contacts the plant material 12, it limits the maximum amountof applied force and protects the plant material 12 from damage. To sealthe open end of bag 14, the user manually lowers pressure strip 24 ontothe selected portion of bag 14 that lies over the sealing strip 26, andapplies pressure until the open end of bag 14 is sealed. When sealing iscomplete, the user manually raises pressure strip 24 and second platen18, and removes plant material 12 within sealed bag 14 from sealingmachine 10.

[0028]FIG. 5 illustrates one embodiment of a sealed product 50, whereinplant material 12 has been sealed within bag 14 using one embodiment ofthe present invention. For illustrative purposes, the plant material 12in FIG. 5 comprises a fern bunch, however, those skilled in the art willreadily appreciate that floral product 50 may alternately comprise afloral arrangement, greenery, or other floral plant material typicallyused in the floral industry. As seen in FIG. 5, the plant material 12lies completely within the interior volume of the sealed bag 14.Further, as the compressible member 20 limits the maximum amount offorce applied to plant material 12 during the sealing process, floralproduct 50 has a substantially vacuum-packed appearance. That is, theforce applied by compressible member 20 evacuates a substantial amountof the air contained within the interior volume of the bag 14, althoughit should be noted that at least some air may remain within the interiorvolume of bag 14 even after sealing. However, even though the plantmaterial 12 has been subjected to some amount of force, the fragileleaves and stems of plant material 12 have not been substantiallycrushed or damaged. Thus, the present invention permits the sealedproduct 50 to enjoy a much longer shelf life than plants that are notpacked and sealed according to the present invention.

[0029] As those skilled in the art will readily appreciate, manyvariations can readily be applied to the present invention withoutdeparting from the essential characteristics. For example, theembodiments shown in the Figures depict second platen 18 moving intopressing engagement with plant material 12 positioned on first platen14, however, the present invention also contemplates embodiments whereinboth first and second platens 16, 18 move towards each other. As such,there is no requirement that the first and second platens 16, 18 behingedly attached. Moreover, the figures illustrate compressible member20 as a single-piece foam pad however, any materials known in the artmay suffice, and compressible member(s) 20 may comprise a single-pieceor a plurality of separate pieces. The only requirement is that thematerial used for compressible member 20 substantially protects theobject during the packaging process, and limit the maximum amount ofpressure applied to the object. Finally, while plant material 12 is usedto illustrate the exemplary embodiments, those skilled in the art willunderstand that any material, fragile or not, may be sealed using thesealing machine 10 of the present invention.

[0030] Accordingly, the present invention may be carried out in otherspecific ways than those set forth herein without departing from theessential characteristics of the invention. The present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

What is claimed is:
 1. A sealing machine for sealing plant materialwithin a bag comprising: a first platen; a second platen movable withrespect to said first platen between open and closed positions; a gapbetween said first and said second platens when said second platenassumes the closed position; a sealing strip to heat the bag and sealthe plant material within the bag; and a compressible member disposed insaid gap between said first and second platens, said compressible membercontacting the bag and applying pressure to the bag to substantiallyevacuate air from within the bag without damaging the plant materialwithin the bag.
 2. The sealing machine of claim 1 wherein said first andsecond platens are hingedly attached.
 3. The sealing machine of claim 1further comprising a heating unit, and wherein said sealing strip isoperatively connected to said heating unit.
 4. The sealing machine ofclaim 3 further comprising a pressure strip that opposes said sealingstrip, said pressure strip contacting and applying pressure to the bag.5. The sealing machine of claim 4 wherein said heating unit is operableto heat said sealing strip to a range of about 40° C. to about 100° C.6. The sealing machine of claim 1 wherein said compressible memberlimits the maximum amount of pressure applied to the plant material inthe bag to a range of about 5 lbs. per square inch to about 20 lbs. persquare inch.
 7. The sealing machine of claim 1 further comprising afluid cylinder, said fluid cylinder moving said second platen intopressing engagement with said first platen.
 8. The sealing machine ofclaim 7 wherein said fluid cylinder is a pneumatic cylinder.
 9. Thesealing machine of claim 1 wherein said compressible member comprises afoam pad.
 10. A method of sealing a bag containing plant material, saidmethod comprising: forming a gap between a first platen and a secondplaten, said second platen being movable with respect to said firstplaten between open and closed positions; applying pressure to the plantmaterial within the bag with a compressible member disposed in said gap,such that the pressure evacuates substantially all of the air from thebag without damaging the plant material within the bag; sealing theplant material within the bag by heating the bag.
 11. The method ofclaim 10 wherein applying pressure to the plant material within the bagcomprises moving said second platen towards the closed position.
 12. Themethod of claim 11 wherein moving said second platen towards the closedposition includes actuating a fluid cylinder operatively connected tosaid second platen.
 13. The method of claim 10 wherein applying pressureto the plant material within the bag comprises limiting the maximumamount of pressure applied to the plant material with said compressiblemember.
 14. The method of claim 13 wherein the maximum amount ofpressure applied to the plant material with said compressible member iswithin the range of about 5 lbs. per square inch to about 20 lbs. persquare inch.
 15. The method of claim 10 wherein sealing the plantmaterial within the bag comprises disposing a selected portion of thebag over said sealing strip.
 16. The method of claim 15 wherein sealingthe plant material within the bag further comprises heating the sealingstrip to a temperature within a range of about 40° C. to 90° C.
 17. Themethod of claim 16 wherein sealing the plant material within the bagfurther comprises directing a pressure on said selected portion of thebag for a period of about 1 second to about 10 seconds.
 18. A packedfloral product comprising: a bag; a floral plant sealed within the bag;and the bag being substantially evacuated of air such that the packedfloral product has a substantially vacuum-packed appearance.
 19. Thepacked floral product of claim 18 wherein the floral plant materialcomprises greenery.
 20. The packed floral product of claim 19 whereinthe greenery is a fern bunch.
 21. The packed floral product claim 18wherein the floral plant material is a floral arrangement.
 22. Thepacked floral product of claim 18 wherein substantially all of the airwithin the bag is evacuated by: forming a gap between a first platen anda second platen, the second platen being movable with respect to thefirst platen between open and closed positions; applying pressure to thefloral plant within the bag with a compressible member disposed in thegap, such that the pressure evacuates substantially all of the air fromwithin the bag without damaging the floral plant; and sealing the floralplant within the bag by heating the bag.